honestly ive searched through the stickied posts (compilation of proofs) and some other threads, but i think i was just too blind to see it if this was already posted,

anyway, i was told that:

if a row/column of a matrix is a SCALAR MULTIPLE of another (in the same matrix)

then its det is 0,

hmm, i really tried this with some examples and its true,

can anyone prove this? i dont wanna present my answer without any proofs